TOI 762 A b and TIC 46432937 b: Two Giant Planets Transiting M-dwarf Stars
J. D. Hartman, Daniel Bayliss, Rafael Brahm, Edward M. Bryant, Andrés Jordán, G. Á. Bakos, Mélissa J. Hobson, Elyar Sedaghati, X. Bonfıls, Marion Cointepas, J. M. Almenara, Khalid Barkaoui, Mathilde Timmermans, George Dransfield, Elsa Ducrot, Sebastián Zúñiga-Fernández, M. J. Hooton, P. P. Pedersen, F. J. Pozuelos, A. H. M. J. Triaud, M. Gillon, Emmanuël Jehin, William C. Waalkes, Zachory K. Berta-Thompson, Steve B. Howell, Elise Furlan, G. Ricker, R. Vanderspek, Sara Seager, Joshua N. Winn, Jon M. Jenkins, David Rapetti, Karen A. Collins, David Charbonneau, Christopher J. Burke, David R. Rodriguez
Abstract
Abstract We present the discovery of TOI 762 A b and TIC 46432937 b, two giant planets transiting M-dwarf stars. Transits of both systems were first detected from observations by the NASA TESS mission, and the transiting objects are confirmed as planets through high-precision radial velocity observations carried out with Very Large Telescope/ESPRESSO. TOI 762 A b is a warm sub-Saturn with a mass of 0.251 ± 0.042 M J , a radius of 0.744 ± 0.017 R J , and an orbital period of 3.4717 days. It transits a mid-M-dwarf star with a mass of 0.442 ± 0.025 M ☉ and a radius of 0.4250 ± 0.0091 R ☉ . The star TOI 762 A has a resolved binary star companion, TOI 762 B, that is separated from TOI 762 A by 3.″2 (∼319 au) and has an estimated mass of 0.227 ± 0.010 M ☉ . The planet TIC 46432937 b is a warm super-Jupiter with a mass of 3.20 ± 0.11 M J and radius of 1.188 ± 0.030 R J . The planet’s orbital period is P = 1.4404 days, and it undergoes grazing transits of its early M-dwarf host star, which has a mass of 0.563 ± 0.029 M ☉ and a radius of 0.5299 ± 0.0091 R ☉ . TIC 46432937 b is one of the highest-mass planets found to date transiting an M-dwarf star. TIC 46432937 b is also a promising target for atmospheric observations, having the highest transmission spectroscopy metric or emission spectroscopy metric value of any known warm super-Jupiter (mass greater than 3.0 M J , equilibrium temperature below 1000 K).